Ore-concentrator.



N0. 718.970. PATENTED JAN. 27, 1903. F. L. BARTLETT. ORE GONUENTRATOR.

APPLICATION FILED MAY 16, 1902. N0 MODEL C J i L M 3 n I i c M 4 m a c HM. H l y l j l W W W W 11x p when the wash-water comes on from the side.

a cross-section on the line w 00 of Fig. 1.

UNlTED STATES PATENT OFF-ICE.

FRANK L. BARTLETT, or DENVER, COLORADO.

ORE-GONOENTRATOR.

SPECIFICATION formingpart of Letters Patent No. 718,970, dated January 27, 1903.

Application filed m 16,1902. Serial No. 107,560. (No model.)

To all whont it may concern.-

Be it known that I, FRANK L. BARTLETT, a citizen of the United States of America, and a resident of Denver, Arapahoe county, State of Colorado, have invented certain new and useful Improvements in Ore-Concentrators,

of which the following is a specification.

My invention relates to ore-concentratorsf and it relates particularly to an improved construction of riffles adapted to be used on the shaking-table patented tome May 8,1900, No. 648,908. I have found that in'the operation of tables of this class where the ore is separated by a side wash of water carrying the light material laterally over the ri-ffles the particular shape of the riiiies is a very essential thing and that it is necessary to so construct them that the ore as it comes onto the table from the feedbox and travels along between the ribs should have sufiicient time to settle and become stratified before it is subjected to the action of the fresh side wash-water. By allowing the ores to stratify before they are acted upon by the wash-water the finer and heavier ores have time to settle 'to the bottom of the grooves and are thus protected from being carried over the riffies According to my present improvement I carry the rifiles from the upper end of the table well down toward the lower end with very nearly their entire height, so as to pro-- tect the slimesand fine ores as long as possible, then abruptly tapering them olf to the end of the table and introducing the side wash-water across the abruptly-tapering portion near the lower end and not at any other point. By thus tapering the rifiles and puttingon the side wash within a comparatively short space at the lower end of the table the ore is allowed to remain a comparatively long time protected by the high riffles of the upper end of the table and with no wash-water eX-. cept what comes on with the ore through the fe d-box.

. illustrate my invention by means of the accompanying drawings, in which- Figure l is a plan view of my table, showing the several descending shelves. Fig. 2 is Fig.

3 is a plan of the riffies, on an enlarged scale.

4, 5, and Garecross-sectious of the riffies, taken at w, y, and z of Fig. 3. Fig. 7 is a vertical sectional view showing one of the rifiles in elevation, on an enlarged scale.

A represents the table proper, as shown in fer to make the riflies perpendicular onthe lower side, the upper side being curved or convex, somewhat thicker at the base than at the upper edge, and with the upper edge rounded.

The surface of the table is somewhat lower on the lower side of the riffies than on the upper side, the angle adjacent to the upper side of the riffies formingachannel into which the fine ores settle and stratify under the shaking action of the table.

In practice I make the riffles one-half inch in height at the upper end of the table, de-

These sevcreasing this height slowly and gradually to a point well down toward the lower end of the table and preferably to a point opposite or below the end of the feed-box. From this point the narrow riffles taper abruptly to the end of the table, coming down to the sawtooth cross-section shown in Fig. 4. The line' where the abrupt taper begins is nearer the lower end of the table on the lower shelf than on the middle shelf and lower on the middle than on the upper, so that any fine ores was ed over by the wash-water are kept at the lower end of the table at all times and do not get mixed with the coarse material which comes over the upper end. i I

The dotted lines a a, a (JP, and 'a a. represent the lines where the abrupt taper begins on the upper, middle, and lower shelves, respectively. The side-wash-water pipes for clear wasnwater' are opposite the abruptly-taperingportion of. the riflies, so that the side wash is all applied near the lower end' of the table and within a comparatively short distance.

' By the'time the ores reach the point a, &c.,

' the fine ores have had time to become stratified and'settledto the bottom of the grooves, and when-thepoint a, is reached the light material is thrown rapidly to-the top of the riflles and washed over the side'of the table,

1.: The herein-described ore-concentrator consisting of a laterally-inclined shaking-tahis having longitudinal riflles which gradually and slowlydecreasein height from the upper end to a point near-the lower end and gradually andslowly decrease in height from a of the table. 1 a 3: The .herein described consisting of a-laterally-inclined shaking-tathe upper end to a-point below thefeed-box and thence taper abruptlyto the lower end ore-concentrator ble having a feed-box extendingal'ongitsupper edgeand a feedwatersupply'.pipe 'extending along the upper edge below the-feed- -b0x and having longitudinal frifiles which gradually and slowly decreasein height from ally and .slowly'decreasing in height fromthe.

upper end of the table to a'poi'nt near-the lower end and thence tapering abruptly to the lower end of the table, the point'where' the abrupt taper begins being nearer the lower end in each successive shelf from the 7 upper to the lower shelf. l thence taper abruptly to the lower end of, the 'tahley 2. The herein-described ore-concentrator" consisting of alaterally-inclined shakingmable havin g a feed-box extending along its upperedge and having longitudinal riflies which a. The herein-described ore-concentrator v consisting of a laterally-inclined shaking-table havinglongitndinal riffies tapering or'decreasing in height more rapidly near the 6 lower end of the table than through the body of the table. y -v Signed at Denver, Golorad0,this -l4-th day of March, 1902,. Y FRANK L. BARTLETT.

' Witnesses: FRANK W. HOPKINS, LLEWELYN JONES. 

